Hi Scotty,
I own 2 Mercedes, a2010 GLK 350 4 matic with 85000 km and a a 2012 c350 4 matic with 115000 km. I had one mechanic tell me I can get away with using regular 85?octane gas and another telling me that I must use minimum 91 octane or I risk ruining my engine/s. What advice could you offer?
thanks
Kalman Strauss
I had a new 2018 BMW M5 that BMW said to run on premium (91+) as I think they do on all their vehicles. The first time I took it in for an oil change they plugged it in to the scanner (or read the key memory, I’m not sure) and said, “I see you’re running premium gas, that’s good”). I was shocked the ECU was able to tell them that, and it made me concerned that using a lower grade might lead to warranty disputes if anything ever went wrong with the car. I have since sold that car but am wary of gas grades in any newer car.
they probably just looked at ignition timing